While GameSpot was not expecting to see any official assets for Nintendo's DS titles until the Gamers' Summit later this week, an update on one of GameStop's product pages has our wheels turning. While the rest of the retailer's database entries for Nintendo DS titles have remained basically unchanged since E3, a recent update to the page for Super Mario 64 DS (called Super Mario 64x4 at E3) features new box art for the title.

Featuring what seems to be a totally original piece of artwork featuring the game's four playable characters, the box art is a far cry from the usual mock-up boxes that GameStop uses as placeholders. The box also lacks the "For Display Only" notice and "Rating Pending" logos, instead featuring the Nintendo logo and an "E" for Everyone rating.

Faced with this evidence, a source inside Nintendo told GameSpot News that he was "inclined to believe that [the artwork in question] is real."

What does it matter? If GameStop has indeed received an official piece of box art, or even official artwork from which to fashion its own box art, it would be a strong indication that Super Mario 64 DS will launch with the system on November 21. Another launch title currently known is Activision's Spider-Man 2, which has a similar box art shown on the site.

Supporting the theory that GameStop received these assets directly from Nintendo, the site also sports authentic-looking box art for Mario Power Tennis that is not available from Nintendo's press artwork repository, where the game is still titled Mario Tennis. The title Mario Power Tennis, said our source, is definitely official.

GameSpot will have full coverage of the Nintendo Gamers' Summit, including the whole scoop on the Nintendo DS' launch lineup, later this week.